CBD may help against depression: what is known about antidepressant effects of CBD?
Depression — a serious and common disease that affects 5% of adults, which is approximately 280 million people worldwide. Women suffer from depressive disorders almost twice as often as men, while modern antidepressant medication (AD) is not effective in every third case [1].
What is a depressive episode?
A depressive episode is a period of depressed mood (feeling of sadness, irritability, emptiness) that lasts most of the day, almost every day, for at least two weeks. Depression is characterized by a loss of pleasure or interest in any activity. Other symptoms of depression include: poor concentration, feelings of excessive guilt, hopelessness, thoughts of death or even suicide, sleep disturbances, changes in appetite or weight, feeling excessive and constant fatigue [2]. The lifetime risk of suicide in people with untreated depression is 20%.
Does CBD help with depression?
Right now we don't know enough to be sure. Scientists need more time and funding for the research. So far, the antidepressant properties of CBD are tested in animal models of depression, and the results indicate that CBD has a rapid antidepressant effect [3]. For example, a single injection of CBD reduces depressive-like behavior in mice and the effect was comparable to such ADs as imipramine and fluoxetine [4]. In another experiment systemic injection of CBD reduced anxiety and cardiovascular effects 24 hours after intense stress (immobilization) in rats. Also, daily injections of CBD (3 and 30 mg/kg) for 15 days reduced depressive-like behavior in animals. Notably, CBD also helped improve synaptic connections between neurons [3].
How does CBD reduce depression?
It is hypothesized that the mechanism of CBD antidepressant action depends on the activation of a certain type of serotonin receptor (5-HT1A). Due to this, CBD may contribute to the therapeutic effect of those antidepressants that enhance serotonergic transmission. In another experiment CBD (7 mg/kg) enhances the effect of a subeffective dose (5 mg/kg) of fluoxetine (AD, a selective serotonin reuptake inhibitor, SSRI), but not of desipramine (tricyclic antidepressant) [5]. This indicates, CBD has a synergistic effect with antidepressants from the SSRI group.
While scientific research continues, people are already actively using CBD [6]. Recently, a survey of 1,483 people who use CBD for various medical conditions was conducted. Among respondents, nearly 400 people reported using CBD to improve their mood, and 250 patients reported that CBD worked "very well on its own" [7].
References:
1. https://www.psychiatrist.com/jcp/depression/pr...
2. https://www.who.int/news-room/fact-s....
3. https://pubmed.ncbi.nlm.nih.gov/298691...
4. https://www.ncbi.nlm.nih.gov/pmc/artic....
5. https://pubmed.ncbi.nlm.nih.gov/29885468/